Revenues and Segment Information, Revenue by Product (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Revenue from External Customer [Line Items]
Revenues	$ 27,879	$ 27,249	$ 28,933	$ 24,263	$ 28,730	$ 30,849	$ 31,015	$ 26,439	$ 108,324	[1]	$ 117,033	[1]	$ 93,980	[1]
Corporate [Member]
Revenue from External Customer [Line Items]
Revenues									2		4		5
Other Revenues [Member] | Corporate [Member]
Revenue from External Customer [Line Items]
Revenues									2		4		5
Refining [Member]
Revenue from External Customer [Line Items]
Revenues									103,746		113,093		90,258
Refining [Member] | Gasoline and Blendstocks [Member]
Revenue from External Customer [Line Items]
Revenues									42,798		46,596		40,347
Refining [Member] | Distillates [Member]
Revenue from External Customer [Line Items]
Revenues									51,942		55,037		41,680
Refining [Member] | Other Product Revenues [Member]
Revenue from External Customer [Line Items]
Revenues									9,006		11,460		8,231
Ethanol [Member]
Revenue from External Customer [Line Items]
Revenues									3,606		3,428		3,324
Ethanol [Member] | Ethanol [Member]
Revenue from External Customer [Line Items]
Revenues									2,889		2,713		2,764
Ethanol [Member] | Distillers Grains [Member]
Revenue from External Customer [Line Items]
Revenues									717		715		560
Renewable Diesel [Member]
Revenue from External Customer [Line Items]
Revenues									970		508		393
Renewable Diesel [Member] | Renewable Diesel [Member]
Revenue from External Customer [Line Items]
Revenues									$ 970		$ 508		$ 393

[1] Includes excise taxes on sales by certain of our international operations of $5,595 million, $5,626 million, and $5,573 million for the years ended December 31, 2019, 2018, and 2017.